Damage control: Masao Yoshida (left), the late former chief of the Fukushima No. 1 nuclear plant, speaks to reporters at the plant in November 2011 as Goshi Hosono, then Cabinet minister in charge of the crisis, looks on. | KYODO

Did late No. 1 plant head avert or facilitate nuclear crisis?

When Masao Yoshida met reporters from major media outlets for the first time on Dec. 12, 2011, the then-chief manager of the Fukushima No. 1 plant left a strange impression on those present.

Yoshida remained calm and quiet throughout the joint interview, although he was known for exerting impassioned leadership that barely spared the nuclear plant from suffering the same explosive fate as Chernobyl, and thus mitigated the level of radioactive fallout in the Tohoku region.

“I apologize from the bottom of my heart. That’s the first thing I will say,” Yoshida told the reporters, saying the triple meltdowns had caused great trouble to everyone in Japan but especially those in Fukushima Prefecture.

Three days later, he left the plant and Tokyo Electric Power Co. later announced he had esophagus cancer. When Yoshida, 58, died of the cancer Tuesday after a long fight, the news made big headlines across the country.

A Tepco spokesman said the utility is not sure if he was aware of the disease at the time of his only news conference. Many Japanese have praised his bravery in continuing to battle the crisis as well as the bureaucratic tendencies of Tepco’s top management.

Yet while not much spotlighted, Yoshida may have been partly responsible for ignoring the dangers of potentially giant tsunami and for not taking enough measures to bolster the plant against major damage, even though expert advisers in 2008 had warned Tepco about the threat.

Yoshida was known for a strong leadership style that kept united plant workers fighting the meltdown crisis that broke out in March 2011, triggered by the quake-tsunami disasters.

He became a national hero for containing the crisis. He even defied unreasonable instructions from senior management at Tepco’s head office in managing the disaster, which only added to his reputation as a decisive leader who cared about his employees.

During a March 12, 2011, teleconference, Tepco executive Ichiro Takekuro ordered Yoshida to stop the critical injection of seawater into the wrecked reactor 1 despite the acute need for more coolant to prevent a catastrophic explosion. Yoshida loudly told his staff to stop the injection, as ordered by Takekuro, but at the same time whispered to them that they should never actually do so. Experts later said Yoshida’s judgment was spot on.

“The possibility was high that without him, the (Fukushima) crisis would have escalated further,” former Prime Minister Naoto Kan wrote on his blog Wednesday, after learning of Yoshida’s death.

“Whatever I asked, staff who came to the prime minister’s office from Tepco’s head office didn’t give any organized answers. Yoshida clearly explained the situation. . . . I strongly felt you can trust this guy,” Kan wrote.

But Yoshida was also a Tepco executive and may have been partly to blame for not preventing the disaster in the first place, as indicated in a 2011 interim report by an expert investigatory panel set up by the government.

According to the report, a panel of experts had pointed out to Tepco in February 2008 that the plant was vulnerable to a possible mega-quake and monster tsunami. Yoshida was then the head of Tepco’s nuclear equipment management department.

Based on this warning, Tepco conducted a simulation and concluded that tsunami in excess of 10 meters could hit the Fukushima No. 1 power plant.

Yoshida and Sakae Muto, a fellow Tepco executive, were briefed about the simulation but they didn’t take any effective measures, believing the projection was based only on a worst-case scenario and was thus unrealistic, the report showed.

“A few years before the magnitude-9.0 Tohoku earthquake struck northeastern Japan on 11 March, a scientific consensus had begun to coalesce around the idea that a Jogan-like event could happen again. But that consensus did not influence seismic risk assessments, tsunami
preparedness, or a review of the hardiness of the Fukushima Daiichi nuclear power plant.”

“Many seismologists had thought that the offshore fault north of Tokyo was fairly simple and uniform. The ocean plate diving beneath Japan, the thinking went, should stick and slowly build up enough stress to rupture the fault. And the fault should fail segment by segment in large but not huge earthquakes. That’s how the fault seemed to have behaved in recent centuries, with quakes of magnitude 7 to 8 or so popping off on any one segment every few decades or few centuries.”